Known in the art is a device for clamping a circular saw blade (SU, A, 891268), consisting of a drive plate mounted on a shaft, a driven plate and a central clamping member in the form of a Belville spring which is connected to a pneumatic or hydraulic cylinder by means of a lever. This construction of the clamping device is inefficient both because of the central clamping which calls for large clamping forces and because of the need to have an auxiliary pneumatic or hydraulic actuator.
Also known in the art is a device for clamping a circular saw blade (SU, A, 1046044) in which a circular saw blade is held between a pair of plates by means of clamping members provided in the peripheral parts of the plates. The clamping members are in the form of spring-biased pins connected to an actuator and interconnecting the drive and driven plates, the pins being received in through holes of the plates.
This construction makes it possible to lower clamping forces at each clamping member in comparison with the central clamping of a circular saw blade, but the design of the clamping members calls for a pneumatic actuator necessary for both clamping and release of the circular saw blade. In addition, this device does not allow a rapid change of a circular saw blade to be carried out since each clamping member is to be brought to the pneumatic actuator and aligned with its piston rod for release. Moreover, in clamping a new circular saw blade, it is necessary to align the holes of the saw blade wih the pins of the clamping members simultaneously at different points. As the circular saw blade is suspended on a cable, it is rather difficult to perform this operation, and it takes much time to change the saw blade. A loss of time for a saw blade change results in downtime of the rolling mill, hence in a decrease in its output.
Known in the art is a device for clamping a circular saw blade (cf. Catalog "Cutting Machines for Rolling Mills" (in Russian), Ed. by A.I. Tselikov. TsNIIINFORMTYaZHMASH A 14-70, Part II. 1971. p. 161).
This clamping device consists of drive and driven plates. The drive plate is rigidly secured to a shaft, and a circular saw blade and the driven plate are mounted on a centering hub of the drive plate. The plates and saw blade have coaxial holes spaced along a circle, and clamping members in the form of circular saw blade fastening bolts are inserted in these holes.
When this device is used, it takes 25 to 30 minutes to change a circular saw blade. This time loss is undesirable as the rolling mill has to be stopped during the saw blade change so that output of the rolling mill is lowered. The time is lost for undoing the bolts, removing them, removing the saw blade and driven plate, installation of the new saw blade and bolt tightening. Time is mainly lost in undoing and tightening of the bolts and in the installation of the saw blade. Since it is not desirable to withdraw the bolts from their holes, two persons should install the bolts on either side of the circular saw blade. But if the bolts are left in their holes, it is difficult to install the circular saw blade because it is necessary to align the saw blade holes with the bolts which move out of their correct position within the limits allowed by clearances, the holes being aligned concurrently with the circular saw blade installation on its seat. In carrying out this operation the circular saw blade can more frequently then not hit at the ends of the bolts to damage the thread which may result in difficulties in running down the nuts.